With reference to inexpensive digital therometers, there is a place where I live (Greenville, SC) called Harbour Freight Tools (I think it is a national chain). Last week I was there and they had these really cute little digital therometers, called Instant Read Digital Therometer, Item # 46430, with extra battery and a pocket carrier, for sale at about $6.00 each. So I bought two of them, not really expecting much in terms of accuracy.
Later back at the ranch I compared the Instant Reads to a very expensive digital therometer that has been my standard for several years. Surprise, the cheapos were right on target, and true to advertising, the readout is almost instantaneous.